Views on scientific consensus predict levels of concern and support for action. People who think scientists mainly agree that global warming is happening are 25 to 30 percentage points more likely than others to think it poses a great threat to the world's environment, to call it extremely or very important personally, and to say the federal government should do much more about it. They're also twice as likely, in an open-ended question, to call global warming the world's greatest environmental problem.
Similarly, people who say weather patterns in their area have grown more unstable in recent years are much more apt -- by 15 to 29 percentage points -- to call global warming highly important, to say it poses a very serious problem and to say the government should do more about it.
Another important factor is familiarity with the subject, and this has grown: Fifty-eight percent of Americans feel at least moderately well-informed about global warming, up about 15 points from the 1997 and 1998 polls, done by researchers at The Ohio State University.
Indeed, these factors -- seeing unstable or warmer weather patterns, feeling well-informed about global warming and believing there's scientific consensus about it -- are, in a statistical model, the strongest predictors of belief that global warming is occurring, concern about its impact and support for government action to mitigate it.
As in previous ABC News polling, more people see global warming as a near-future threat rather than as a current one. Fewer than four in 10 Americans, 38 percent, think it's a serious problem now. But far more -- exceeding eight in 10 -- think it will become a serious problem in the future if nothing is done to reduce it. And most of them, six in 10, say that future is fewer than 50 years off.
About half, 49 percent, think it'll be a "very" serious problem for the United States if nothing is done; more, 57 percent, think it'll be a "very" serious problem for the world.
Levels of Threat:
Present and Future
|Serious problem now||38%|
|Threatens you a
in the future
|Threatens future generations
a great deal
A look at specific possible impacts tells a similar story. Sizable majorities see threats across the board, but lowest on the list is the sense of personal threat; instead the future is a deeper concern. While 62 percent of Americans say global warming threatens them personally, far fewer, 25 percent, say it threatens them "a great deal." By contrast, 88 percent think it threatens future generations -- 60 percent, a great deal.
Unsurprisingly, people who are sure global warming is happening, or who see it as a big threat -- either personally or to future generations -- are far more apt than others to view it as a serious problem overall, and to favor government action to address it.
In addition to the 60 percent who say global warming poses a significant threat to future generations, 56 percent say it threatens plant and animal species a great deal, and about half say it poses a great deal of threat to the world's environment overall and to poor people in undeveloped countries.
Fewer, about a third, see a great deal of threat to other Americans or to people in other industrialized countries, presumably given their greater resources to mitigate the impacts.